Component measuring device

ABSTRACT

A component measuring device for measuring the quantity and/or the property of a given component in a specimen by calorimetrically measuring a test strip includes a tip mount on which is to be mounted a tip having the test strip, and a photometric unit. The photometric unit comprises a light-emitting element that applies light to the test strip while the tip is mounted on the tip mount, a light-detecting element that detects light reflected from the test strip, and a holder in which is held the light-emitting element and the light-detecting element. The holder possesses a passage through which passes the light and the reflected light. A light-transmissive member closes the passage with a sealing member interposed therebetween in a portion of the holder which faces the test strip. The component measuring device can also be provided with a stain detecting device which is adapted to detect a stain on the light-transmissive member.

This application is the U.S. national stage application of InternationalApplication No. PCT/JP2004/007305 filed on May 21, 2004 designating theUnited States, the entire content of which is incorporated herein byreference. This application is also based on and claims priority under35 U.S.C. § 119(a) to Japanese Application No. 2003-144131 filed on May21, 2003, Japanese Application No. 2003-201933 filed on Jul. 25, 2003and Japanese Application No. 2003-328879 filed on Sep. 19, 2003, theentire content of each of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a component measuring device formeasuring the quantity and/or the property of a component in question,such as for measuring a blood glucose level.

BACKGROUND ART

There is known a blood glucose level measuring device (blood componentmeasuring device) for measuring a blood glucose level. The blood glucoselevel measuring device quantifies a blood glucose level by opticallymeasuring (calorimetrically measuring) a color that is developed by atest strip depending on the amount of glucose in blood.

The conventional blood glucose level measuring device includes aphotometric unit having a light-emitting element and a light-detectingelement. The photometric unit measures the color of the test strip byapplying light to the test strip and measuring the intensity ofreflected light.

The photometric unit has a passage for passing therethrough the light tobe applied to the test strip and the reflected light from the teststrip. The passage is open in a portion of the photometric unit whichfaces the test strip.

The photometric unit of the above component measuring device suffers aproblem in that dust or foreign matter tends to be trapped in thephotometric unit. The problem has heretofore been addressed by JapanesePatent Laid-Open No. Hei 3-95438 and Japanese Patent Laid-Open No. Hei3-95439.

Japanese Patent Laid-Open No. Hei 3-95431 and Japanese Patent Laid-OpenNo. Hei 3-95440 have proposed placing a transparent plate on the frontsurface of a photometric unit to prevent dust from entering thecomponent measuring device.

With the conventional blood glucose level measuring device, however,since the opening is not sealed in a liquid-tight manner, blood appliedto the test strip may be trapped into the passage in the photometricunit, and it is difficult to remove the trapped blood from the teststrip.

Furthermore, if a liquid such as water and an aqueous solution ofethanol is used to wash away a stain such as dust, blood, urine, andfingerprint, then the liquid may possibly enter the blood glucose levelmeasuring device.

If foreign matter such as water and blood is introduced into the passagein the photometric unit, then the measured value of the blood glucoselevel varies, resulting in a reduction in the measurement accuracy.

Stains such as dust, dirt, fingerprint and blood may be applied to thetransparent plate. The applied stains are liable to cause the measuredvalue of the blood glucose level to vary, resulting in a reduction inthe measurement accuracy. Therefore, stains on the transparent plateneed to be detected.

Heretofore, it has been customary to detect such stains according to awhite level checking process. According to the white level checkingprocess, a white pattern is placed at the tip end of the photometricunit, and when a stain is applied to the transparent plate, the sum ofthe amount of reflected light from the white pattern and the amount ofreflected light from the transparent plate is reduced.

More specifically, a stain is detected by the white level checkingprocess as follows: A tip having a test strip (white) is mounted on thephotometric unit. The tip is irradiated with light emitted from thelight-emitting element of the photometric unit, and reflected lightreflected from the tip is detected by the light-detecting element. Astain on the transparent plate is detected based on the amount of lightdetected by the light-detecting element. If the amount of light detectedby the light-detecting element is smaller than a predeterminedthreshold, then it is determined that the transparent plate is stained.

According to the white level checking process for detecting a stain,however, the strong reflected light from the test strip and the weakreflected light from the stain on the transparent plate are mixed witheach other, tending to fail to detect a stain on the transparent platehighly accurately.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a componentmeasuring device having high measurement accuracy.

Another object of the present invention is to provide a componentmeasuring device having high measurement accuracy, which is capable ofaccurately detecting a stain on a light-transmissive member.

To achieve the above objects, there is provided in accordance with thepresent invention a component measuring device for measuring a quantityand/or a property of a given component in a specimen by calorimetricallymeasuring a test strip, including: a tip mount for removably mounting atip having the test strip; and a photometric unit having alight-emitting element for applying light to the test strip while thetip is being mounted on the tip mount, a light-detecting element fordetecting reflected light reflected from the test strip, and a holderfor accommodating and holding the light-emitting element and thelight-detecting element. The holder has a passage for passing the lightand the reflected light therethrough, and a light-transmissive member isdisposed to close the passage with a sealing member interposedtherebetween in a portion of the holder which faces the test strip.

With this arrangement, dust, blood (specimen), or the like is reliablyprevented from entering into the passage in the photometric unit (intothe photometric unit). Even if dust, the specimen, or the like isapplied to an end of the photometric unit or the like, it can easily andreliably be removed. Therefore, the amount of a blood component inquestion can be measured with high measurement accuracy.

There is also provided in accordance with the present invention acomponent measuring device for measuring a quantity and/or a property ofa given component in a specimen by calorimetrically measuring a teststrip, including: a tip mount for removably mounting a tip having thetest strip; and a photometric unit having a light-emitting element forapplying light to the test strip while the tip is being mounted on thetip mount, a light-detecting element for detecting reflected lightreflected from the test strip, and a holder for accommodating andholding the light-emitting element and the light-detecting element. Theholder has a passage for passing the light and the reflected lighttherethrough, and a light-transmissive member is fixed to the holder bya holder member in a portion of the holder which faces the test strip,and is disposed to close the passage with a sealing member interposedtherebetween.

With this arrangement, dust, blood (specimen), or the like is reliablyprevented from entering into the passage in the photometric unit (intothe photometric unit). Even if dust, the specimen, or the like isapplied to an end of the photometric unit or the like, it can easily andreliably be removed. Therefore, the amount of a blood component inquestion can be measured with high measurement accuracy.

In the component measuring device according to the present invention,the light-transmissive member preferably isolates the test strip and thepassage of the holder from each other with the tip being mounted on thetip mount.

In the component measuring device according to the present invention,the light-transmissive member preferably includes a flat plate and has asurface facing the test strip and lying substantially flush with an endface of the holder.

In the component measuring device according to the present invention,the sealing member is preferably made of an elastomeric material.

In the component measuring device according to the present invention,the tip mount is preferably disposed at an end of the photometric unitwhere the passage is open.

In the component measuring device according to the present invention,the holder member preferably has an abutment portion held in abutmentagainst the light-transmissive member, the abutment portion having anopening for passing the light and the reflected light therethrough.

In the component measuring device according to the present invention,the opening preferably has a cross-sectional area which is substantiallyconstant from an outer end thereof to an inner end thereof.

In the component measuring device according to the present invention,the opening preferably has a cross-sectional area which is progressivelyreduced from an outer end thereof to an inner end thereof.

In the component measuring device according to the present invention,the opening preferably has a cross-sectional area (average) ranging from0.1 to 100 mm².

In the component measuring device according to the present invention,the opening preferably has a cross-sectional shape which issubstantially equal from an outer end thereof to an inner end thereof.

In the component measuring device according to the present invention, ifit is assumed that the maximum spaced distance between opposite innersurfaces of the opening in the vertical cross section is represented byL₁ [mm] and the thickness of the opening by L₂ [mm], then the ratioL₂/L₁ should preferably satisfy the relationship indicated by 0.1 orgreater.

In the component measuring device according to the present invention,the abutment portion preferably includes a flat plate having a thickness(average) ranging from 0.1 to 10 mm.

In the component measuring device according to the present invention,the opening area of the inner end of the opening should preferably begreater than the opening area of the passage of the holder.

There is also provided in accordance with the present invention acomponent measuring device for measuring a quantity and/or a property ofa given component in a specimen by calorimetrically measuring a testmember, including: a tip mount for removably mounting a tip having thetest member; a photometric unit having a light-emitting element forapplying light to the test member of the tip for measurement, alight-detecting element for detecting reflected light reflected from thetest member, and a holder for accommodating and holding thelight-emitting element and the light-detecting element; alight-shielding test tip for being removably mounted on the tip mount,wherein the holder has a passage for passing the light and the reflectedlight therethrough, and a light-transmissive member is disposed in aportion of the holder which faces the test member; and stain detectingmeans for detecting a stain on the light-transmissive member based on anamount of light detected by the light-detecting element when light isemitted from the light-emitting element of the photometric unit andlight is detected by the light-detecting element while the test tip isbeing mounted on the tip mount, wherein the stain detecting means isarranged to determine that there is a stain on the light-transmissivemember if the amount of light detected by the light-detecting element isgreater than a threshold in detecting a stain on the light-transmissivemember.

With this arrangement, a stain on the light-transmissive member can bedetected with high accuracy. Since an amount of a blood component inquestion is prevented from being measured while the light-transmissivemember is being stained, the measurement accuracy is increased. Sincethe component measuring device has the light-transmissive member, dust,the specimen, or the like is reliably prevented from entering into thepassage in the photometric unit (into the photometric unit), so that anamount of a blood component in question can be measured with highmeasurement accuracy.

In the component measuring device according to the present invention,the test tip preferably has a lid-like member for covering a distal endof the tip mount.

In the component measuring device according to the present invention, atleast the lid-like member of the test tip is preferably black or dark incolor.

In the component measuring device according to the present invention,the distance from the distal end of the tip mount to an inner wall ofthe lid-like member at a distal end thereof is preferably 10 mm orgreater while the test tip is being mounted on the tip mount.

There is also provided in accordance with the present invention acomponent measuring device for measuring a quantity and/or a property ofa given component in a specimen by calorimetrically measuring a testmember, including: a tip mount for removably mounting a tip having thetest member; a photometric unit having a light-emitting element forapplying light to the test member of the tip for measurement, alight-detecting element for detecting reflected light reflected from thetest member, and a holder for accommodating and holding thelight-emitting element and the light-detecting element, wherein theholder has a passage for passing the light and the reflected lighttherethrough, and a light-transmissive member is disposed in a portionof the holder which faces the test member; and stain detecting means fordetecting a stain on the light-transmissive member based on an amount oflight detected by the light-detecting element when light is emitted fromthe light-emitting element of the photometric unit and light is detectedby the light-detecting element, wherein the stain detecting means isarranged to determine that there is a stain on the light-transmissivemember if the amount of light detected by the light-detecting element isgreater than a threshold in detecting a stain on the light-transmissivemember.

With this arrangement, a stain on the light-transmissive member can bedetected with high accuracy. Since an amount of a blood component inquestion is prevented from being measured while the light-transmissivemember is being stained, the measurement accuracy is increased. Sincethe component measuring device has the light-transmissive member, dust,the specimen, or the like is reliably prevented from entering into thepassage in the photometric unit (into the photometric unit), so that anamount of a blood component in question can be measured with highmeasurement accuracy.

In the component measuring device according to the present invention, astain on the light-transmissive member is preferably detected while thetip is not being mounted on the tip mount.

In the component measuring device according to the present invention, astain on the light-transmissive member is preferably detected when apower supply of the component measuring device is turned on.

The component measuring device according to the present inventionpreferably has a stain detecting mode for detecting a stain on thelight-transmissive member.

The component measuring device according to the present inventionpreferably further includes storage means. A stain on thelight-transmissive member is preferably detected after measurement, anda detected result is preferably stored in the storage means.

In the component measuring device according to the present invention,when a stain on the light-transmissive member is not detected,information stored in the storage means is used.

In the component measuring device according to the present invention,when the component measuring device is powered on with the tip beingmounted on the tip mount, a stain on the light-transmissive member isnot detected and information stored in the storage means is used.

The component measuring device according to the present inventionpreferably further includes: indicating means for indicating a detectedresult produced in detecting a stain on the light-transmissive member.

In the component measuring device according to the present invention,the light-transmissive member is preferably disposed to close thepassage with a sealing member interposed therebetween.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view showing an internal structure of a firstembodiment of a component measuring device according to the presentinvention;

FIG. 2 is a sectional side elevational view of the component measuringdevice shown in FIG. 1;

FIG. 3 is a block diagram of the component measuring device shown inFIG. 1;

FIG. 4 is a vertical cross-sectional view of a photometric unit of thecomponent measuring device shown in FIG. 1;

FIG. 5 is a vertical cross-sectional view showing the structure of aphotometric unit of a second embodiment of a component measuring deviceaccording to the present invention;

FIG. 6 is a vertical cross-sectional view showing the structure of aphotometric unit of a third embodiment of a component measuring deviceaccording to the present invention;

FIG. 7 is a vertical cross-sectional view of a tip;

FIG. 8 is a vertical cross-sectional view of the tip shown in FIG. 7which is mounted on the component measuring device;

FIG. 9 is a side elevational view showing the manner in which a blood issampled using the tip shown in FIG. 7;

FIG. 10 is a vertical cross-sectional view showing the structure of aphotometric unit of a fourth embodiment of a component measuring deviceaccording to the present invention;

FIG. 11 is a graph showing characteristic curves plotted according to ablack level checking process when stains (stained states) of alight-transmissive member are changed;

FIG. 12 is a graph showing characteristic curves plotted according to awhite level checking process when stains (stained states) of alight-transmissive member are changed;

FIG. 13 is a plan view of an embodiment (arrangement) of a test tipmounted on the component measuring device according to the fourthembodiment;

FIG. 14 is a sectional plan view of the test tip shown in FIG. 13;

FIG. 15 is a timing chart showing the relationship between the amount oflight detected by a light-detecting element when there is no stain on alight-transmissive member and an operating procedure in a normalmeasurement mode;

FIG. 16 is a timing chart showing the relationship between the amount oflight detected by a light-detecting element when there is a stain on alight-transmissive member and an operating procedure in a normalmeasurement mode;

FIG. 17 is a timing chart showing the relationship between the amount oflight detected by a light-detecting element 42 and an operatingprocedure in a normal measurement mode;

FIG. 18 is a flowchart of a control process of a control means of thecomponent measuring device according to the fourth embodiment;

FIG. 19 is a flowchart of the control process of the control means ofthe component measuring device according to the fourth embodiment;

FIG. 20 is a flowchart of the control process of the control means ofthe component measuring device according to the fourth embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION

Component measuring devices according to the present invention will bedescribed in detail below with respect to preferred embodimentsillustrated in the accompanying drawings. Prior to describingembodiments of component measuring devices according to the presentinvention, an embodiment of a tip (component measuring tip) for use onthe component measuring devices according to the present invention willfirst be described below.

FIG. 7 is a vertical cross-sectional view of a tip, and FIG. 8 is avertical cross-sectional view of the tip shown in FIG. 7 which ismounted on the component measuring device. The lower side in FIGS. 7 and8 will be referred to as “proximal end” and the upper side as “distalend”.

A tip 5 shown in FIG. 7 includes a bottomed tubular tip body 51, a thintube 52 projecting from a bottom 511 of the tip body 51, and a teststrip 53 as a test member disposed in the tip body 51.

The tip body 51 serves as a mount for supporting the test strip 53 andmounting the tip 5 on a distal end (tip mount) of a photometric unit 4of a component measuring device 1 to be described later.

The tip body 51 includes the bottom 511, a barrel 513, and a flange 514disposed on the outer circumferential surface of the proximal end of thebarrel 513. A seat 512 for fixing the test strip 53 thereto is disposedon an inner surface of the bottom 511. The test strip 53 has an outercircumferential edge (fixed portion 533) fixed to the seat 512 by fusionbonding, adhesive bonding, or the like.

The barrel 513 serves as a mount for mounting the tip 5 on the tip endof the photometric unit 4 of the component measuring device 1.Specifically, as shown in FIGS. 8 and 9, the tip end of the photometricunit 4 (holder 43) is fitted in the barrel 513 of the tip body 51,thereby mounting the tip 5 on the photometric unit 4 of the componentmeasuring device 1. The state shown in FIG. 8 will hereinafter referredto as “tip mounted state”.

The thin tube 52, which serves to sample a blood (specimen), has aspecimen introduction passage 520 defined therein. The specimenintroduction passage 520 extends in a direction substantiallyperpendicular to the test strip 53, and has a specimen inlet port 523 inthe distal end thereof and a specimen outlet port 527 in the proximalend thereof.

Since the blood is supplied through specimen introduction passage 520due to a capillary action to the test strip 53, the inside diameter(average) of the specimen introduction passage 520 should preferably bein the range from about 0.2 to 2.0 mm, and more preferably be in therange from about 0.3 to 1.0 mm. If the inside diameter of the specimenintroduction passage 520 is too large, then it is difficult to deliverthe blood by way of a capillary action, and if the inside diameter istoo small, then the blood is supplied at a low rate and it takes a longperiod of time to supply a sufficient amount of blood to the test strip53.

The inside diameter (cross-sectional area) of the specimen introductionpassage 520 may be constant or vary along the longitudinal direction ofthe specimen introduction passage 520.

The length (entire length) of the specimen introduction passage 520should preferably be in the range from about 1 to 10 mm, and morepreferably be in the range from about 2 to 5 mm. If the length of thespecimen introduction passage 520 is too large, then it takes long timeto deliver the blood by way of a capillary action, and if the length istoo small, then the blood 18 may possibly be applied to the outersurface of the bottom of the tip body 51 in the state shown in FIG. 9.

As shown in FIG. 7, the distal end and the proximal end of the thin tube52 provide a specimen inlet end 521 and a specimen outlet end 525,respectively.

A groove 522 is defined in the end face of the specimen inlet end 521 incommunication with the specimen introduction passage 520. In theillustrated structure, the groove 522 is a straight groove extendingdiametrically across the thin tube 52. The groove 522 has opposite endsthat are open at the outer circumferential surface of the thin tube 52.

The specimen outlet end 525 (near the test strip 53) of the thin tube 52is formed as a land slightly projecting into the tip body (toward theproximal end). The end face of the specimen outlet end 525 has a groove(second groove) 526 communicating with the specimen introduction passage520. In the illustrated structure, the groove 526 is a straight grooveextending diametrically across the thin tube 52. The groove 526 hasopposite ends that are open at the outer circumferential surface of theprojecting portion (the thin tube 52).

As shown in FIG. 7, a gap 54 is present on the side of the test strip 53near the thin tube 52, i.e., between the test strip 53 and the innersurface of the bottom 511 of the tip body 51. The gap 54 has a functionto assist in spreading the blood on the test strip 53.

A specimen reservoir 55 in the form of an annular recess held incommunication with the gap 54 and deeper than the gap 54 is disposed inan outer circumferential area of the gap 54. The blood that has beenspread radially through the gap 54 is trapped in the specimen reservoir55 and prevented from moving radially outwardly (into the region of thetest strip 53 that is fixed by adhesive bonding, fusing, or the like).Therefore, even if the blood is supplied excessively, the excessiveblood is prevented from leaking out. Thus, the photometric unit 4 of thecomponent measuring device 1 is prevented from being contaminated byblood deposits.

A spacer 56 is disposed radially outwardly of the seat 512 on the innersurface of the bottom 511 of the tip body 51. The spacer 56 serves asspacing means for keeping the test strip 53 and the holder 43 out ofcontact with each other when the tip 5 is mounted in place.

The spacer 56 includes a plurality of (e.g., four at angular intervalsof 90°) protrusions arrayed circumferentially on the inner surface ofthe bottom 511. As shown in FIG. 8, the spacer 56 abuts against the tipend of the holder 43 of the photometric unit 4 to prevent the tip end ofthe holder 43 from contacting the test strip 53.

The spacer 56 thus protects the test strip 53 and prevents the bloodspread in the test strip 53 from being applied to and contaminating thephotometric unit 4.

The spacer 56 also has a function to abut against the tip end of theholder 43 to keep the test strip 53 and a light-emitting element 41 anda light-detecting element 42 of the photometric unit 4 spaced from eachother by a constant distance. Therefore, a measurement error which wouldotherwise be caused if the distance changed to vary the opticalcharacteristics is minimized for increased measurement accuracy.

The tip 5 is not limited to the structure having the flange 514 and thethin tube 52, but may be in the form of a flat plate, a sheet, or astick, for example.

The tip body 51 and the thin tube 52 are made of a rigid material havinga predetermined rigidity. The rigid material may be any of various resinmaterials including acrylic resin, polystyrene, polyethylene,polypropylene, hard polyvinyl chloride, polycarbonate, polymethylmethacrylate, ABS resin, polyester, polyphenylene sulfide (PPS),polyamide, polyimide, and polyacetal, or a polymer alloy, and a polymerblend which contains one or more of the above resin materials. Of thesematerials, highly hydrophilic materials such as acrylic resin ormaterials that have been hydrophilicized are particularly suitable forquickly introducing and spreading the specimen.

The hydrophilicizing process may be a physically activating process suchas plasma processing, glow discharge, corona discharge, and ultravioletirradiation, or the addition (coating) of a surface active agent,water-soluble silicone, hydroxypropyl cellulose, polyethylene glycol,polypropylene glycol, or the like.

The test strip 53 includes a carrier capable of absorbing the blood(specimen), the carrier carrying (being impregnated with) a reagent(coloring reagent). The carrier should preferably include a porous film(sheet-like porous base). The porous film should preferably have a porediameter small enough to filtrate red cells in the blood.

If the carrier in the form of a porous film is impregnated with areagent that reacts with oxygen as a substrate such as in an oxidasicreaction, then even when the blood is spread in the test strip 53 andcovers the blood reception side thereof, oxygen in the atmosphere issupplied from the reaction side (opposite side) to keep the reaction inrapid progress for allowing a colored state to be detected withoutremoval of the blood.

The carrier of the test strip 53 may be a sheet-like porous base such asa non-woven fabric, a woven fabric, an oriented sheet, or the like,other than a porous film.

The carrier such as a porous film may be made of any of variouspolyesters, polyamides, polyolefins, polysulfons, celluloses, or thelike. However, because the carrier needs to be impregnated with anaqueous solution with a reagent dissolved therein and also needs toquickly absorb and spread blood when blood is sampled, the carriershould preferably be made of a hydrophilic material or a hydrophilicizedmaterial. The hydrophilicizing process may be the same as thosedescribed above.

The reagent used to impregnate the carrier (porous film) may be glucoseoxidase (GOD), peroxidase (POD), or a coloring agent (coloring reagent)such as 4-aminoantipyrine orN-ethylN-(2-hydroxy-3-sulfopropyl)-m-toluidine for measuring a bloodglucose level. Depending on a component to be measured, the reagent maybe of a substance which reacts a component in question in blood (givencomponent), such as ascorbate oxidase, alcohol oxidase, alcoholdehydrogenase, galactose oxidase, fructose dehydrogenase, cholesteroloxidase, cholesterol dehydrogenase, lactate oxidase, lactatedehydrogenase, bilirubin oxidase, and xanthin oxidase, or a coloringagent (coloring reagent) as described above. The reagent may contain abuffer such as a phosphoric acid buffer. However, the reagent is notlimited to the types and components described above.

The shape and structure of the test strip 53 will be described below.The test strip 53 should preferably be of a circular shape. However, theshape of the test strip 53 is not limited to a circular shape, but maybe selected where necessary from various shapes including an ellipticalshape, a quadrangular shape such as a square shape, an elongaterectangular shape, a lozenge shape, or the like, a triangular shape, ahexagonal shape, and an octagonal shape.

The test strip 53 has an annular ridge 532 disposed radially inwardly(toward the center) from the outer circumferential edge (outermost edge)thereof and projecting in the same direction as a protrusion 531thereof. The annular ridge 532 is of a circular shape around theprotrusion 531 at its center and has a tip end inserted in the specimenreservoir 55.

The annular ridge 532 has a function to limit the blood from beingspread in the test strip 53 for thereby preventing excessive blood fromflowing radially outwardly beyond the annular ridge 532, thus preventinga contamination due to blood deposits.

Though the annular ridge 532 is not limited to any diameters, it shouldpreferably have a diameter in the range from 75 to 95%, and preferably85 to 95%, of the outside diameter of the test strip 53.

The annular ridge 532 should preferably have a width in the range fromabout 0.03 to 1.0 mm, and more preferably in the range from about 0.05to 0.5 mm. The annular ridge 532 should preferably have a height in therange from about 0.02 to 1.0 mm, and more preferably in the range fromabout 0.05 to 0.4 mm.

The shape and dimensions (diameter, width, height, etc.) of the annularridge 532 may be selected depending on the shape, etc. of the tip body51.

As shown in FIG. 7, the test strip 53 has a fixed portion 533 positionedin its outer peripheral edge area, i.e., radially outwardly of theannular ridge 532. The fixed portion 533 is fixed to the seat 512 of thetip body 51 by fusing, adhesive bonding, or the like.

The test strip 53 may be fixed to the end face of the specimen outletend 525 by fusing, adhesive bonding, or the like. In this manner, thetest strip 53 may be supported on and fixed to the tip body 51 morestably. Furthermore, the test strip 53 may be prevented from hinderingthe spreading of the blood due to a gap which would otherwise bedeveloped if deformed (curved, strained, or undulated).

FIG. 9 is a side elevational view showing the manner in which a blood issampled using the tip 5. As shown in FIG. 9, a blood is sampled bypiercing a fingertip (or an earlobe) with a needle, a surgical knife, orthe like, letting a small amount (e.g., about 1 to 6 μL) of blood 18flow from the pierced region onto the skin.

The tip 5 is mounted on the distal end (tip mount) of the photometricunit 4 of the component measuring device 1, bringing the end face of thespecimen inlet end 521 into contact with the skin. The blood 18 on thefingertip flows through the groove 522 into the specimen inlet port 523,and then flows through the specimen introduction passage 520 toward theproximal end under the suction of a capillary action until it reachesthe specimen outlet port 527. At this time, since the blood 18 on thefingertip is effectively drawn in from side openings of the groove 522(which are open at the outer circumferential surface of the thin tube52), the blood 18 is not excessively scattered on the skin and hencesuffers a reduced loss.

When the blood reaches the specimen outlet port 527, it is contacted andabsorbed by the protrusion 531 of the test strip 53. A portion of theblood flows through the groove 526 into the gap 54. After having flowedinto the gap 54, the blood is absorbed and spread in the adjacent teststrip 53, and further spread radially outwardly. As the test strip 53absorbs and spreads the blood particularly in the vicinity of theprotrusion 531, a new suction force is developed in the specimenintroduction passage 520 for continuously supplying the blood to thetest strip 53.

When the spreading of the blood in the test strip 53 is completed, acomponent in question (e.g., glucose) in the blood reacts with thereagent carried by the test strip 53, producing a color depending on theamount of the component in question. The colored test strip 53 isphotometrically measured to measure the intensity of the color forthereby determining the amount (blood glucose level) of the component inquestion in the blood.

Though a test strip has been described as a test member, the test memberis not limited to a test strip, but may be anything insofar as it canchange reflected light depending on the component in question.

A component measuring device according to the present invention will bedescribed below with reference to preferred embodiments which are shownin the accompanying drawings.

First Embodiment

A first embodiment of a component measuring device according to thepresent invention will be described below.

FIG. 1 is a plan view showing an internal structure of the firstembodiment of the component measuring device according to the presentinvention, FIG. 2 is a sectional side elevational view of the componentmeasuring device shown in FIG. 1, FIG. 3 is a block diagram of thecomponent measuring device shown in FIG. 1, and FIG. 4 is a verticalcross-sectional view of a photometric unit of the component measuringdevice shown in FIG. 1. The left side in FIGS. 1, 2, and 4 will bereferred to as “proximal end” and the right side as “distal end”.

The component measuring device (blood component measuring device) 1shown in these figures has a casing 2 in which a printed-circuit board 3is disposed. A photometric unit 4 is disposed in the distal end of thecasing 2. A liquid crystal display (LCD) unit 9 is installed in a windowof the casing 2.

Control means 10 including a microcomputer is mounted on theprinted-circuit board 3 for controlling various operations of thecomponent measuring device 1. The control means 10 has a processor forcalculating a blood component (e.g., glucose) in question based on asignal from the photometric unit 4. The processor also performshematocrit value correcting calculations and temperature correctingcalculations.

The photometric unit 4 has a light-emitting element (light-emittingdiode) 41 and a light-detecting element (photodiode) 42 which are housedand held in a holder 43. The light-emitting element 41 is electricallyconnected to the control means 10, and the light-detecting element 42 iselectrically connected to the control means 10 through an amplifier, notshown, and an A/D converter 49.

The light-emitting element 41 operates in response to a signal from thecontrol means 10 to emit pulsed light at predetermined time intervals.The pulsed light has a period in the range from about 0.5 to 3.0 msec.,for example, and the emission time of one pulse is in the range fromabout 0.05 to 0.3 msec.

The wavelength of the pulsed light should preferably be in the rangefrom about 500 to 720 nm and more preferably in the range from about 580to 650 nm.

A tip (component measurement tip) 5 incorporating therein a test strip53 as described above is removably mounted on the distal end of theholder 43 (photometric unit 4). Specifically, a ring-shaped (annular)fitting portion 44 projects in a predetermined position from the distalend of the holder 43. When the tip 5 is mounted on the distal end of theholder 43 (tip mounted state), the proximal end of the tip body 51 isfitted in the fitting portion 44, fixing the tip 5 to the holder 43 (seeFIG. 8). According to the present invention, therefore, the distal endof the holder 43 (the end of the photometric unit 4 where a firstpassage 431 and a second passage 432, described later, are open) servesas a tip mounting portion.

In the tip-mounted state, the distal end face of the holder 43 faces thetest strip 53 in the tip 5. When the light-emitting element 41 is turnedon, light emitted from the light-emitting element 41 is applied to thetest strip 53, and reflected light reflected from the test strip 53 isdetected by the light-detecting element 42, which photoelectricallyconverts the light into a signal. The light-detecting element 42 outputsan analog signal depending on the amount of detected light. The analogsignal is amplified as desired, and then converted by the A/D converter49 into a digital signal, which is applied to the control means 10.

The present invention resides in features of the photometric unit 4.These features will be described in detail later on.

The component measuring device 1 has a power supply 6, a power supplyvoltage detector 7, a switch circuit 8, a control oscillator 11, a clockoscillator 12, a data storage unit (storage means) 13, a buzzer outputunit 14, an external output unit 15, and a temperature measuring unit16.

Cells 61 are loaded in the power supply 6. The power supply voltagedetector 7 detects the voltage of the cells 61, and outputs a detectedvoltage value (detected value) to the control means 10 for checking theremaining amount of electric energy in the cells 61.

The switch circuit 8 detects input signals from various switchesdescribed below, and applies the signals to the control means 10. Theswitches include a power supply switch, a stored data readout switch, atime setting/changing switch, a reset switch, a buzzeractivation/inactivation selector switch, and a 50 Hz/60 Hz commercialpower supply frequency selector switch.

The power supply switch can be turned on and off by pressing anoperation button 31. The other switches can be actuated by operatingeither one or more of operating members 32, 33, 34 in combination.

The control oscillator 11 serves as a timer for generating clock pulsesat certain time intervals, and supplies an operation reference signalfor the microcomputer (microprocessing unit: MPU) of the control means10.

The clock oscillator 12 serves as a clock for specifying absolute time(date and time). The clock oscillator 12 generates clock pulses atcertain time intervals, and supplies an operation reference signal for aclock control circuit in the control means 10.

The data storage unit 13 has a first memory (RAM), a second memory(ROM), and a third memory (nonvolatile RAM) as a rewritable nonvolatilememory. Measured values (photometric data) input from the photometricunit 4 are stored according to a predetermined format in the firstmemory.

The second memory stores a table representative of the relationship(analytical curve) between absorbances determined from photometricvalues and amounts of a blood component in question.

The third memory stores in advance calibration values inherent to theindividual device. The inherent calibration values include a rated valuefor amounts of reflected light and a corrective coefficient forabsorbance calculations.

The buzzer output unit 14 energizes a buzzer to emit sound based on asignal from the control means 10.

The external output unit 15 serves to output data of a determined amountof a blood component in question to an external device such as apersonal computer. The external output unit 15 has a communicationdriver such as RS232C. For performing infrared communications, theexternal output unit 15 has an infrared radiation emitter and a drivercircuit therefor.

The temperature measuring unit 16 has a temperature sensor (thermistor)for measuring an ambient temperature. The temperature measuring unit 16measures a temperature from time to time, and temperature informationfrom the temperature measuring unit 16 is stored in the first memory ofthe data storage unit 13. Temperature information read from the firstmemory is input to the control means 10 for use in calculations fortemperature-correcting an amount of a blood component in question.

The present invention resides in features of the structure of thephotometric unit 4 described above. These points (features) will bedescribed in detail below with reference to FIG. 4.

As described above, the photometric unit 4 has the holder (photometricblock) 43 in which the light-emitting element 41 and the light-detectingelement 42 are fixed in position. The holder 43 has a first passage 431for passing and guiding light emitted from the light-emitting element 41therethrough to the test strip 53, and a second passage 432 for passingand guiding reflected light reflected by the test strip 53 to thelight-detecting element 42.

The first passage 431 and the second passage 432 are united together(join each other) in the distal end of the holder 43, and are open atthe distal end of the holder 43. The distal end of the holder 43 has anopening 433 where the first passage 431 and the second passage 432 areopen.

The opening 433 should preferably be of a circular shape. However, theshape of the opening 433 may be selected where necessary from variousshapes including an elliptical shape, a quadrangular shape such as asquare shape, an elongate rectangular shape, and a lozenge shape, atriangular shape, a hexagonal shape, and an octagonal shape.

A recess 434 is defined in the distal end of the holder 43, i.e., theportion thereof which confronts the test strip 53 in the tip mountedstate (the portion facing the test strip 53 in the tip mounted state),with the first passage 431 (the opening 433) being positionedsubstantially centrally.

An annular recess 435 is defined around the recess 434 in communicationwith the recess 434 and deeper than the recess 434.

An O-ring 46 is placed in the annular recess 435, and alight-transmissive member 45 is placed and fixed in the recess 434. Thefirst passage 431 and the second passage 432 (hereinafter simplyreferred to as “passage”) in the holder 43 are sealed by thelight-transmissive member 45 with the O-ring 46 interposed therebetween.

The light-transmissive member 45 may be fixed (secured) to the holder 43by fitting, fusion bonding, threading, adhesive bonding, or the like.

In the tip mounted state, the light-transmissive member 45 isolates thetest strip 53 and the passage in the holder 43 (the photometric unit 4)from each other.

If the passage in the holder 43 is not closed, i.e., if the passage isopen at the distal end of the holder 43, then water or blood (specimen)spread in the test strip 53 may be unduly introduced into the passage.If water or blood is introduced, then it is difficult to remove theintroduced water or blood, and the introduced water or blood tends toblock the optical path or attenuate the amount of light, affecting thecharacteristics of the optical system. Therefore, the subsequentmeasurement of an amount of a blood component in question tends to beadversely affected, resulting in a reduction in the measurementaccuracy.

According to the present invention, since the passage in the holder 43is closed, water or blood (specimen) is reliably prevented from beingintroduced into the passage. Accordingly, it is possible to measure anamount of a blood component in question with a high level of measurementaccuracy.

As the passage in the holder 43 remains securely closed, even when bloodor the like is applied to the distal end face of the holder 43 (thephotometric unit 4) or the light-transmissive member 45, it can easilyand reliably be washed away by a cleaning liquid such as rubbingalcohol, and water.

As described above, the tip 5 is constructed with various features toprevent the blood supplied to the test strip 53 from being applied tothe photometric unit 4. Since the component measuring device 1 accordingto the present invention allows blood deposits on the photometric unit 4to be easily removed, the tip 5 may be of a simple structure and may bereduced in cost.

According to the present embodiment, the light-transmissive member 45 isin the form of a flat plate and has a distal end face (the face closerto the test strip 53) lying substantially flush with the distal end faceof the holder 43. With this arrangement, when the light-transmissivemember 45 is washed by the cleaning liquid, dust, blood, or the like isprevented from remaining near the boundary between the holder 43 and thelight-transmissive member 45.

The thickness (average) of the light-transmissive member 45 slightlydiffers depending on the material thereof, and is not limited to anyparticular values. However, it should preferably be in the range fromabout 0.1 to 10 mm and more preferably in the range from about 0.3 to 3mm. If the light-transmissive member 45 is too thin, its mechanicalstrength may be lowered. If the light-transmissive member 45 is toothick, then the photometric unit 4 is unfavorably large in size.

The light-transmissive member 45 should preferably be of a shapecomplementary to the opening 433, and should preferably be of a sizelarge enough to cover the opening 433.

The light-transmissive member 45 may be made of any of various glassmaterials or various resin materials.

The holder 43 may be made of any of various resin materials includingacrylic resin, polystyrene, polyethylene, polypropylene, hard polyvinylchloride, polycarbonate, polymethyl methacrylate, ABS resin, polyester,polyphenylene sulfide (PPS), polyamide, polyimide, and polyacetal, or apolymer alloy, a polymer blend, or the like which contains one or moreof the above resin materials, or any of various metal materialsincluding aluminum, aluminum alloy, titanium, titanium alloy, andstainless steel.

The light-transmissive member 45 is not limited to a flat plate, but maybe of a lens shape.

One or more coating layers for desired purposes may be provided on thesurface of the light-transmissive member 45. The coating layer or layersmay be provided for the purpose of increasing the measurement accuracy,or for the purpose of preventing the light-transmissive member 45 frombeing damaged, or the like.

For the purpose of increasing the measurement accuracy, the coatinglayer or layers may include an anti-reflection coating (AR coating) forpreventing light emitted by the light-emitting element 42 from beingreflected by the surface (proximal end surface) of thelight-transmissive member 45, an anti-reflection coating for preventingreflected light reflected by the test strip 53 from being reflected bythe surface (distal end surface) of the light-transmissive member 45, alow-pass filter for selectively passing light having a wavelength equalto or lower than 720 nm as disturbing light (particular, infraredradiation) greatly affects the measurement accuracy, a bandpass filterfor selectively passing light having a wavelength in the range fromabout 500 to 720 nm (corresponding to the wavelength of light emittedfrom the light-emitting element 41), or the like.

For the purpose of preventing the light-transmissive member 45 frombeing damaged, the coating layer may include a reinforcing coating layer(hard coating layer) made primarily of an Si-based material, an Al-basedmaterial, a polyfunctional acrylic material, a urethane resin-basedmaterial, and a melamine resin-based material.

The O-ring 46 is made of an elastomeric material and has a diameter inthe vertical cross section which is greater than the depth of theannular recess 435. When the light-transmissive member 45 is placed inthe recess 434, the O-ring 46 is held in reliable contact with both theholder 43 and the light-transmissive member 45, thereby increasing thesealing (liquid-tight or air-tight sealing) of the passage in the holder43 for further improving the advantages described above.

The elastomeric material may be any of various rubber materials(particularly those vulcanized) including natural rubber, isoprenerubber, butadiene rubber, styrene-butadiene rubber, nitrile rubber,chloroprene rubber, butyl rubber, acrylic rubber, ethylene-propylenerubber, hidrin rubber, urethane rubber, silicone rubber, andfluorocarbon rubber, or any of various plastic elastomers includingstyrene-based elastomer, polyolefin-based elastomer, polyvinylchloride-based elastomer, polyurethane-based elastomer, polyester-basedelastomer, polyamide-based elastomer, polybutadiene-based elastomer,transpolyisoprene-based elastomer, fluocarbon rubber-based elastomer,and chlorinated polyethylene-based elastomer. One or two or more of theabove materials may be mixed together for use as the elastomericmaterial.

The O-ring 46 is not limited to the illustrated position, but may bepositioned on an outer circumferential portion of the light-transmissivemember 45.

Second Embodiment

A second embodiment of a component measuring device according to thepresent invention will be described below.

FIG. 5 is a cross-sectional view showing the structure of thephotometric unit of the second embodiment of the component measuringdevice according to the present invention.

The component measuring device according to the second embodiment willbe described below basically with respect to differences thereof fromthe component measuring device according to the first embodiment, andidentical parts will not be described below.

According to the second embodiment, the photometric unit 4 differs instructure. Other details of the second embodiment are identical to thoseof the first embodiment. Specifically, the photometric unit 4 shown inFIG. 5 differs from the photometric unit 4 according to the firstembodiment in that a holder member 47 is added.

The holder member 47 serves to fix the light-transmissive member 45 tothe holder 43. The holder member 47 includes an abutment portion 471held in abutment against the light-transmissive member 45 and a barrel473 integrally formed with the abutment portion 471.

The barrel 473 serves as a mount for mounting the holder member 47 onthe distal end of the holder 43. Specifically, as shown in FIG. 5, thedistal end of the holder 43 is inserted into the barrel 473 of theholder member 47 until the holder member 47 is mounted on (fitted over)the holder 43.

When the holder member 47 is mounted on the distal end of the holder 43with the O-ring 46 placed in the annular recess 435 and thelight-transmissive member 45 placed in the recess 434, the abutmentportion 471 abuts against the light-transmissive member 45, and pressesthe light-transmissive member 45 toward the holder 43. The O-ring 46presses the light-transmissive member 45 against the abutment portion471 under its own resiliency. The light-transmissive member 45 is thusfixed to the holder 43.

An adhesive reservoir 436 in the form of a plurality of ring-shapedrecesses is defined in the outer circumferential surface of the distalend of the holder 43. The adhesive reservoir 436 is supplied with anadhesive, fixing (securing) the holder member 47 to the holder 43.

The holder member 47 may be fixed (secured) to the holder 43 by fitting,fusion bonding, threading, or the like, rather than adhesive bonding. Ifthe holder member 47 is fixed to the holder 43 by fitting or threading,then the light-transmissive member 45 and the O-ring 46 may convenientlybe replaced when necessary.

The barrel 473 has a fitting portion 44 on the outer circumferentialsurface of the proximal end thereof for fitting engagement with theproximal end of the tip 5.

The abutment portion 471 is in the form of a flat plate having anopening 472 defined substantially centrally therein for passingtherethrough light emitted from the light-emitting element 41 andreflected light reflected from the test strip 53.

The opening 472 has a cross-sectional shape that is of a substantiallyequal shape (similar shape) at any position from the distal end (outerend) to the proximal end (inner end), and has a substantially constantcross-sectional area from the distal end to the proximal end.Specifically, the angle formed between the inner surface of the opening472 and the abutment portion 471 (the distal end and the proximal end ofthe abutment portion 471) is essentially 90°.

With this arrangement, even when a finger or the like is brought intocontact with the distal end face of the holder member 47, the finger orthe like is prevented from contacting the distal end face (outer face)of the light-transmissive member 45 (contact prevention capability).

The cross-sectional shape of the opening 472 should preferably be ofsubstantially the same as the shape (as viewed in plan) of thelight-transmissive member 45. The cross-sectional area (average) of theopening 472 should preferably be set to a value that is slightly smallerthan the area of the light-transmissive member 45. With thisarrangement, the light-transmissive member 45 is reliably pressed andfixed to the holder 43 by the abutment portion 471 (the holder member47) without obstructing the passage of the light and the reflectedlight. The above contact prevention capability is also sufficientlyperformed.

From the above standpoint, the cross-sectional area (average) of theopening 472 should preferably be in the range from about 0.1 to 100 mm².

As shown in FIG. 5, if it is assumed that the maximum spaced distancebetween opposite inner surfaces of the opening 472 in the vertical crosssection (the maximum diameter if the cross-sectional shape of theopening 472 is circular) is represented by L₁ [mm] and the thickness ofthe opening 72 (corresponding to the thickness of the abutment portion471 according to the present embodiment) by L₂ [mm], then the ratioL₂/L₁ should preferably satisfy the relationship indicated by 0.1 orgreater, and more preferably the relationship indicated by the rangefrom 0.1 to 0.4. This allows the above contact prevention capability tobe performed suitably.

The average thickness of the abutment portion 471 (the thickness of theopening 472) L₂ slightly differs depending on the material of the holdermember 47, and is not limited to any particular values. However, itshould preferably be in the range from about 0.1 to 10 mm. If theabutment portion 471 is too thin, then the mechanical strength of theabutment portion 471 (the holder member 47) tends to be lowered and theabove contact prevention capability may not be sufficiently performed.If the thickness of the abutment portion 471 is increased in excess ofthe above upper limit, then the photometric unit 4 is unfavorably largein size.

The material of the holder member 47 may be the same as the material ofthe holder 43 as described above.

Third Embodiment

A third embodiment of a component measuring device according to thepresent invention will be described below.

FIG. 6 is a cross-sectional view showing the structure of thephotometric unit of the third embodiment of the component measuringdevice according to the present invention.

The component measuring device according to the third embodiment will bedescribed below basically with respect to differences thereof from thecomponent measuring devices according to the first and secondembodiments, and identical parts will not be described below.

According to the third embodiment, the holder member 47 differs instructure. Other details of the third embodiment are identical to thoseof the second embodiment. Specifically, the photometric unit 4 shown inFIG. 6 differs from the photometric unit 4 according to the secondembodiment in that the opening 472 defined in the holder member 47 has adifferent shape.

The opening 472 according to the present embodiment has across-sectional shape that is of a substantially equal shape (similarshape) at any position from the distal end to the proximal end, and hasa cross-sectional area that is progressively smaller continuously fromthe distal end to the proximal end. Specifically, the inner surface ofthe opening 472 is inclined at a certain angle (θ in FIG. 6) to theabutment portion 471 (the distal end face and the proximal end face ofthe abutment portion 471).

With this arrangement, even when dirt, blood, or the like is applied tothe distal end face of the light-transmissive member 45 and the innersurface of the opening 472 or when a finger or the like is brought intocontact with the distal end face of the light-transmissive member 45,applying fat (fingerprint) or the like thereto, the applied deposit caneasily and reliably be removed.

According to the present embodiment, the opening area of the proximalend of the opening 472 should preferably be lightly smaller than thearea of the light-transmissive member 45.

Particularly, as shown in FIG. 6, the opening area of the proximal end(inner end) of the opening 472 should preferably be greater than theopening area of the passage in the holder 43. With this arrangement,even if slight applied deposits remain in the vicinity of the boundarybetween the light-transmissive member 45 and the opening 472 when stainsapplied to the distal end face of the light-transmissive member 45 andthe inner surface of the opening 472 are removed, the remaining stainsare prevented from obstructing the light path of light from thelight-emitting element 41 and reflected light reflected by the teststrip 53, with the result that the measurement accuracy is preventedfrom being lowered.

The opening 472 may be of a structure whose cross-sectional area isreduced stepwise from the distal end to the proximal end, or may be of astructure having a portion whose cross-sectional area is reduced.

Fourth Embodiment

A fourth embodiment of a component measuring device according to thepresent invention will be described below.

FIG. 10 is a vertical cross-sectional view showing the structure of thephotometric unit of the fourth embodiment of the component measuringdevice according to the present invention. FIG. 10 illustrates that astain 17 is applied to the light-transmissive member 45. The left sidein FIG. 10 will be referred to as “proximal end” and the right side as“distal end”.

The component measuring device according to the fourth embodiment willbe described below basically with respect to differences thereof fromthe component measuring devices according to the first embodiment, andidentical parts will not be described below.

The component measuring device 1 according to the fourth embodiment hasa stain detecting means for detecting a stain on the light-transmissivemember 45. According to the fourth embodiment, the so-called black levelchecking process is employed to detect a stain on the light-transmissivemember 45.

The liquid crystal display unit 9 also functions as indicating means forindicating the result of a process for detecting a stain on thelight-transmissive member 45 as described later.

The second memory of the data storage unit 13 stores thresholds inaddition to the relationship (analytical curve) between absorbancesdetermined from photometric values and amounts of a blood component inquestion.

A process for detecting a stain on the light-transmissive member 45,which is an essential part (feature) of the component measuring device 1according to the present embodiment, will be described below.

The component measuring device 1 is arranged to emit light from thelight-emitting element 41 of the photometric unit 4, detect light withthe light-detecting element 42, and detect a stain on thelight-transmissive element 45 based on the amount of light detected bythe light-detecting element 42.

In the process for detecting a stain on the light-transmissive member45, light detected by the light-detecting element 42 is primarilyemitted from the light-emitting element 41 and reflected by thelight-transmissive element 45 and a stain such as dust, dirt,fingerprint, and blood, for example, applied thereto. As describedabove, the light-detecting element 42 outputs an analog signal dependingon the amount of light detected thereby, and the analog signal isamplified and converted by the A/D converter 49 into a digital signal,which is input to the control means 10. Based on the input digitalsignal representative of the value depending on the amount of lightdetected by the light-detecting element 42, the control means performs apredetermined process (determination or the like) to detect a stain onthe light-transmissive member 45. Therefore, the control means 10 servesas a main part of the stain detecting means.

The component measuring device 1 employs the so-called black levelchecking process to detect a stain on the light-transmissive member 45.The principles of the black level checking process will be describedbelow.

If no stain is applied to the light-transmissive member 45 in an openstate in which nothing is mounted on the distal end of the photometricunit 4 shown in FIG. 4, then light emitted from the light-emittingelement 41 of the photometric unit 4 is not essentially applied to thelight-detecting element 42 (there is no reflecting object).

If a stain 17 is applied to the light-transmissive member 45 in the openstate as shown in FIG. 5, a portion of light emitted from thelight-emitting element 41 of the photometric unit 4 is reflected by thestain 17, and weak reflected light is applied to the light-detectingelement 42.

In the open state, therefore, the amount of light detected by thelight-detecting element 42 is greater as more stain is applied to thelight-transmissive member 45.

If a black (dark) pattern is put on the distal end (distal end side) ofthe photometric unit 4, then since light emitted from the light-emittingelement 41 is not essentially reflected by the black pattern, the amountof light detected by the light-detecting element 42 is greater as morestain is applied to the light-transmissive member 45.

In the process for detecting a stain on the light-transmissive member 45according to the present embodiment, with the tip 5 being not mounted onthe distal end of the photometric unit 4, e.g., in the open state withnothing mounted on the distal end of the photometric unit 4, or in atest tip mounted state in which a light-shielding test tip, describedlater, is mounted on the distal end of the photometric unit 4, light isemitted from the light-emitting element 41 of the photometric unit 4,light is detected by the light-detecting element 42, and a stain on thelight-transmissive member 45 is detected based on the amount of lightdetected by the light-detecting element 42. If the amount of lightdetected by the light-detecting element 42 is greater than a presetthreshold, then it is determined that there is a stain on thelight-transmissive member 45. The threshold may be experimentallydetermined depending on various conditions, for example.

According to the present invention, the phrase “the amount of lightdetected by the light-detecting element 42 is greater than a presetthreshold” includes not only a>b, but also a≧b where “a” represents theamount of light detected by the light-detecting element 42 and “b” thethreshold. Therefore, it may be determined that there is a stain on thelight-transmissive member 45 if a>b, or it may be determined that thereis a stain on the light-transmissive member 45 if a≧b.

Advantages of the black level checking process over the white levelchecking process will be described below.

FIG. 11 is a graph showing characteristic curves plotted according tothe black level checking process when stains (stained states) of thelight-transmissive member 45 are changed. FIG. 12 is a graph showingcharacteristic curves plotted according to the white level checkingprocess when stains (stained states) of the light-transmissive memberare changed.

In the graph of FIG. 11, the vertical axis represents the changing ratioof measured values due to stains, and the horizontal axis the amount oflight detected by the light-detecting element 42 when a light-shieldingtest tip, described later, is mounted on the distal end of thephotometric unit 4.

In the graph of FIG. 12, the vertical axis represents the same changingratio as with FIG. 11, and the horizontal axis the amount of lightdetected by the light-detecting element when an unused tip 5 is mountedon the distal end of the photometric unit.

According to the white level checking process, as shown in FIG. 12, if athreshold value is set as shown, for example, the changing ratio maypossibly be in the range from 80% to 90% even when a measurement OK isdisplayed. It is difficult to set a threshold for appropriatelydetecting a stain.

However, according to the black level checking process, as shown in FIG.11, the changing ratio of measured values and the amount of lightdetected by the light-detecting element 42 are highly correlated, makingit easy to set a threshold for accurately detecting a stain.

A test tip for use in detecting a stain on the light-transmissive member45 will be described below.

FIG. 13 is a plan view of an embodiment (arrangement) of a test tipmounted on the component measuring device according to the fourthembodiment, and FIG. 14 is a sectional plan view of the test tip shownin FIG. 13. The left side in FIGS. 13 and 14 will be referred to as“proximal end” and the right side as “distal end”.

As shown in FIGS. 13 and 14, a test tip (lid) 20 is light-shielding andis removably mounted on the distal end of the photometric unit 4.

According to the present invention, the test tip 20 is of a hollowcylindrical shape (tubular shape) and has a partition 21 disposedtherein. For mounting the test tip 20 on the distal end of thephotometric unit 4, the proximal end of the test tip 20 is fitted overthe distal end of the photometric unit 4. The partition 21 of the testtip 20 and the proximal end of the partition 21 provide a lid-likemember for covering the tip portion of the distal end of the photometricunit 4.

The test tip 20 may be black or dark in color, but should preferably beblack. Though the test tip 20 may be black or dark in its entirety, onlythe lid-like member of the test tip 20 may be black or dark.

With the test tip 20 mounted on the distal end of the photometric unit4, light emitted from the light-emitting element 41 is prevented frombeing reflected by the test tip 20 and external light is prevented fromentering the test tip 20. Thus, unwanted light is prevented from beingapplied to the light-detecting element 42.

When the test tip 20 is mounted on the distal end of the photometricunit 4, the length “a” from the tip of the distal end of the photometricunit 4 to the inner wall of the partition 21 of the test tip 20 shouldpreferably be 10 mm or greater.

With the length “a” being 10 mm or greater, it is possible to reliablyprevent light emitted from the light-emitting element 41 from beingreflected by the test tip 20 and applied to the light-detecting element42 (an ideal non-reflected state or a state highly close thereto isachieved).

The test tip 20 is not limited to the illustrated shape, but may be of ashape suited to the component measuring device 1 for mounting the testtip 20 thereon.

The test tip 20 is not limited to any materials, but may be made of arigid material having a predetermined level of rigidity, for example.The rigid material may be any of various resin materials includingacrylic resin, polystyrene, polyethylene, polypropylene, hard polyvinylchloride, polycarbonate, polymethyl methacrylate, ABS resin, polyester,polyphenylene sulfide (PPS), polyamide, polyimide, polyacetal, etc., ora polymer alloy, a polymer blend, or the like which contains one or moreof the above resin materials.

The component measuring device 1 has a normal measurement mode formaking measurements and a stain detecting mode for detecting a stain onthe light-transmissive member 45.

When the power supply switch is turned on (the power supply is turnedon) while the time setting/changing switch is being turned on, thecomponent measuring device 1 is set to the stain detecting mode. Whenthe power supply switch is turned on while the time setting/changingswitch is being turned off, the component measuring device 1 is set tothe normal measurement mode.

FIG. 15 is a timing chart showing the relationship between the amount oflight detected by the light-detecting element 42 when there is no stainon the light-transmissive member 45 and an operating procedure in thenormal measurement mode. FIG. 16 is a timing chart showing therelationship between the amount of light detected by the light-detectingelement 42 when there is a stain on the light-transmissive member 45 andthe operating procedure in the normal measurement mode. FIG. 17 is atiming chart showing the relationship between the amount of lightdetected by the light-detecting element 42 and the operating procedurein the normal measurement mode. FIGS. 15, 16, and 17 show the amount oflight detected by the light-detecting element 42 on the assumption thatlight is emitted from the light-emitting element 41 even when light isnot actually emitted from the light-emitting element 41.

In the normal measurement mode, when the power supply switch is turnedon, as shown in FIG. 15, the above stain detecting process is performedif the tip 5 is not mounted on the distal end of the photometric unit 4.

It is determined whether there is a stain or not based on the amount oflight detected by the light-detecting element 42.

If it is determined that there is no stain, then when the tip 5 ismounted on the distal end of the photometric unit 4, the liquid crystaldisplay unit 9 displays “OK” indicating that measurements are possible.

It is determined whether the tip 5 is mounted or not based on the amountof light detected by the light-detecting element 42. Specifically, ifthe tip 5 is mounted, then the amount of light detected by thelight-detecting element 42 is greater than if the tip 5 is not mounted.Therefore, a predetermined value is established, and if the amount oflight detected by the light-detecting element 42 is greater than thepredetermined value, then it is determined that the tip 5 is mounted,and if the amount of light detected by the light-detecting element 42 issmaller than the predetermined value, then it is determined that the tip5 is not mounted.

When the operator (user) sees the displayed “OK”, the operator canrecognize that there is no stain and measurements are possible, andperforms the predetermined operating procedure described above.

When the blood is spread into the test strip 53 in the tip 5, the amountof light detected by the light-detecting element 42 is reduced.

If there is a stain, as shown in FIG. 16, then when the tip 5 is mountedon the distal end of the photometric unit 4, the liquid crystal displayunit 9 displays (turns on) a warning indicating that there is a stainand no measurements are possible.

When the operator sees the warning, the operator can recognize thatthere is a stain and no measurements are possible, and wipes or cleansthe light-transmissive member 45, thereby removing the stain from thelight-transmissive member 45.

In the normal measurement mode, as shown in FIG. 17, when themeasurement is over and the tip 5 is removed from the distal end of thephotometric unit 4, the above stain detecting process is performed. Theresult of the stain detecting process is stored in the third memory ofthe data storage unit 13.

When the power supply switch is turned off (the power supply is shutdown) and then turned on again, if the tip 5 is mounted on the distalend of the photometric unit 4, i.e., when power supply switch is turnedon with the tip 5 mounted in place, no stain detecting process isperformed, and the information stored in the third memory (the result ofthe stain detecting process after the preceding measurement is finished)is used.

Specifically, if the result of the stain detecting process after thepreceding measurement is finished indicates no stain, then the liquidcrystal display unit 9 displays “OK” indicating that measurements arepossible.

If the result of the stain detecting process after the precedingmeasurement is finished indicates a stain, then the liquid crystaldisplay unit 9 displays (turns on) a warning indicating that there is astain and no measurements are possible.

In the stain detecting mode, when the power supply switch is turned on,the liquid crystal display unit 9 displays that the stain detecting modeis set.

The user mounts the test tip 20 on the distal end of the photometricunit 4. Then, when a call switch is turned on, the stain detectingprocess is performed.

If there is no stain, then the liquid crystal display unit 9 displays“YES” indicating that there is no stain.

When the user sees the displayed “YES”, the user can recognize thatthere is no stain.

If there is a stain, then the liquid crystal display unit 9 displays“NO” indicating that there is a stain.

When the user sees the displayed “NO”, the user can recognize that thereis a stain, and wipes or cleans the light-transmissive member 45,thereby removing the stain from the light-transmissive member 45. Theuser then operates to perform the stain detecting process, therebyperforming the stain detecting process.

The stain detecting mode includes a detailed stain detecting mode fordisplaying a stain level (e.g., a numerical value thereof). When thecalling switch is turned on while the time setting/changing switch isbeing turned on in the stain detecting mode, the detailed staindetecting mode is set.

In the detailed stain detecting mode, as in the stain detecting mode,the user mounts the test tip 20 on the distal end of the photometricunit 4. Then, when the call switch is turned on, the stain detectingprocess is performed.

If there is no stain, then the liquid crystal display unit 9 displays“YES” indicating that there is no stain.

If there is a stain, then the liquid crystal display unit 9 displays“NO” indicating that there is a stain and also displays the amount oflight detected by the light-detecting element 42 as a numeral indicativeof the level of the stain.

When the user sees the value (numeral) of the amount of light detectedby the light-detecting element 42 as displayed by the liquid crystaldisplay unit 9, the user can recognize the stain level and can take anappropriate action depending on the stain level.

A control process (operation) of the control means 10 of the componentmeasuring device 1 will be described below with reference to FIGS. 18through 20.

FIGS. 18 through 20 are flowcharts a control process of the controlmeans 10 of the component measuring device 1 according to the fourthembodiment. FIGS. 18 and 19 show the control process in the normalmeasurement mode, and FIG. 20 shows the control process in the staindetecting mode. For a simpler description and an easier understanding ofthe invention, some determining (judging) steps are shown as normalsteps and some user's actions are shown as steps in FIGS. 18 through 20.

First, the control process of the control means 10 of the componentmeasuring device 1 in the normal measurement mode will be describedbelow.

As described above, when the power supply switch is turned on while thetime setting/changing switch is being turned off, the componentmeasuring device 1 is set to the normal measurement mode. As shown inFIG. 18, it is determined whether the tip 5 is mounted on the distal endof the photometric unit 4 or not (step S101). If the tip 5 is mounted,then control goes to step S105, and if the tip 5 is not mounted, thencontrol goes to step S102.

In step S102, the light-emitting element 41 is intermittently energizeda plurality of times in periods of one second, and the above staindetecting process is performed in each of the periods.

If no stain is confirmed even in one of the periods in which the staindetecting process is performed, then it is determined that there is nostain, and a flag A indicative of no stain is set (A=1).

If no stain is not confirmed even in one of the periods in which thestain detecting process is performed (the amount of light detected bythe light-detecting element 42 is greater than the preset threshold inall of the periods in which the stain detecting process is performed),it is determined that there is a stain, and the flag A is not set (A=0).

The emission of light from the light-emitting element 41 in step S102 isnot limited to periods of one second.

Then, when the tip 5 is mounted on the distal end of the photometricunit 4 (step S103), it is determined whether the flag A=1 or not (stepS104). If the flag A=1, then the liquid crystal display unit 9 displays“OK” indicating that there is no stain and measurements are possible(step S106), after which control goes to a next process (e.g.,measurement).

If A=0, then the liquid crystal display unit 9 displays (turns on) astain warning indicating that there is a stain and no measurements arepossible (step S107), after which control goes to a next process.

In step S105, it is determined whether a flag C=1 or not. If the flagC=1, then control goes to step S106 to carry out step S106 and thefollowing process. If the flag C=0, then control goes to step S107 tocarry out step S107 and the following process.

The flag C will be described later. The information of the flag C(whether the flag C is 1 or 0) is stored in the third memory of the datastorage unit 13, and will not be erased even when the power supplyswitch is turned off. The information of the flag C is read from thethird memory prior to the decision in step S105.

As shown in FIG. 19, the measurement is over and the measured value isdisplayed by the liquid crystal display unit 9 (step S201), and the usedtip 5 is removed from the distal end of the photometric unit 4 (stepS202). The light-emitting element 41 is intermittently energized aplurality of times in periods of one second, and the above staindetecting process is performed in each of the periods (step S203).

If no stain is confirmed even in one of the periods in which the staindetecting process is performed, then it is determined that there is nostain, and the flag C indicative of no stain is set (C=1). Theinformation of the flag C(C=1) is stored in the third memory of the datastorage unit 13.

If no stain is not confirmed even in one of the periods in which thestain detecting process is performed (the amount of light detected bythe light-detecting element 42 is greater than the preset threshold inall of the periods in which the stain detecting process is performed),it is determined that there is a stain, and the flag C is not set (C=0).The information of the flag C(C=0) is stored in the third memory of thedata storage unit 13.

The emission of light from the light-emitting element 41 in step S203 isnot limited to periods of one second.

Then, when the power supply switch is turned off (step S204), it isdetermined whether the flag C=1 or not (step S205). If the flag C=1,then control goes to a next process. Strictly, the power supply switchis turned off after the necessary process is finished.

If the flag C=0, control goes to step S206 to be described below. Afterhaving performed step S206, control goes to a next process.

If the used tip 5 is not removed from the distal end of the photometricunit 4 in step 202, step S203 is not performed, and the flag C=0.

Specifically, when the power supply switch is turned off with the usedtip 5 being mounted on the distal end of the photometric unit 4 (stepS204), it is determined that the flag C=0 in step S205, and control goesto step S206.

In step S206, the light-emitting element 41 is intermittently energizeda plurality of times in periods of one second (for 30 seconds), and theabove stain detecting process is performed in each of the periods.

If no stain is confirmed even in one of the periods in which the staindetecting process is performed, then it is determined that there is nostain, and the flag C indicative of no stain is set (C=1). Theinformation of the flag C(C=1) is stored in the third memory of the datastorage unit 13.

If no stain is not confirmed even in one of the periods in which thestain detecting process is performed (the amount of light detected bythe light-detecting element 42 is greater than the preset threshold inall of the periods in which the stain detecting process is performed),it is determined that there is a stain, and the flag C is not set (C=0).The information of the flag C(C=0) is stored in the third memory of thedata storage unit 13.

As described above, even when the power supply switch is turned off withthe used tip 5 being mounted on the distal end of the photometric unit4, the stain detecting process is performed in step S206.

The emission of light from the light-emitting element 41 in step S206 isnot limited to periods of one second, and the time in which the emissionof light from the light-emitting element 41 is continued is not limitedto 30 seconds.

The information of the flag C stored in the third memory of the datastorage unit 13 (whether the flag C is 1 or 0) will be used in thedecision of step S105 when the power supply switch is turned on nexttime.

Specifically, when the power supply switch is turned on after the tip 5is mounted next time on the distal end of the photometric unit 4 (whilethe tip 5 is being mounted on the distal end of the photometric unit 4),the information of the flag C is read from the third memory of the datastorage unit 13 prior to the decision of step S105, and used in thedecision of step S105.

Thus, even when the power supply switch is turned on with the used tip 5being mounted on the distal end of the photometric unit 4, information(a warning or the like) obtained in the preceding measurement cycle withrespect to a stain on the light-transmissive member 45 can be displayed.

The control process of the control means 10 of the component measuringdevice 1 in the stain detecting mode will be described below. Thedetailed stain detecting mode will not be described below.

As described above, when the power supply switch is turned on while thetime setting/changing switch is being turned on, the component measuringdevice 1 is set to the stain detecting mode (step S301), as shown inFIG. 20. The test tip 20 is mounted on the distal end of the photometricunit 4 (step S302). When the calling switch is turned on (step S303),the light-emitting element 41 is energized once, and the stain detectingprocess described above is performed (step S304).

If no stain is confirmed, then it is determined that there is no stain,and a flag B indicative of no stain is set (B=1).

If no stain is not confirmed (the amount of light detected by thelight-detecting element 42 is greater than the preset threshold), thenit is determined there is a stain, and the flag B is not set (B=0).

The emission of light from the light-emitting element 41 in step S304 isnot limited to one emission.

Then, it is determined whether the flag B=1 or not (step S305). If theflag B=1, then the liquid crystal display unit 9 displays “YES”indicating that there is no stain (step S306), after which control goesto a next process.

If the flag B=0, then the liquid crystal display unit 9 displays staininformation representative of “NO” indicating that there is a stain(step S307), after which control goes to a next process.

With the component measuring device 1, as described above, since thepassage in the holder 43 is closed by the light-transmissive member 45,dust, water, blood (specimen), or the like is reliably prevented fromentering the passage in the holder 43 (the photometric unit 4).Therefore, the amount of a blood component in question can be measuredwith high measurement accuracy.

Inasmuch as a stain on the light-transmissive member 45 is detectedaccording to the black level checking process, a stain on thelight-transmissive member 45 can be detected highly accurately. Thus,measurements while the light-transmissive member 45 is being stained areprevented from occurring, and the measurement accuracy is furtherincreased.

In the fourth embodiment, a holder member 47 may be incorporated as inthe second embodiment and the third embodiment described above (thesecond embodiment and the third embodiment may be applied).

Though the component measuring device according to the present inventionhas been described above based on the illustrated embodiments, thepresent invention is not limited to the illustrated embodiments, and thestructures of various parts may be replaced with any desired structureshaving the same functions. Furthermore, other desired structures may beadded.

The present invention may be a combination of two or more desiredstructures (features) of the above embodiments.

According to the present invention, the light-emitting element and thelight-detecting element are not limited to one set, but may be employedin a plurality of sets. It is possible to provide a light-emittingelement and a light-detecting element for detecting a stain in additionto a light-emitting element and a light-detecting element for measuringa component. However, it is preferable to use the same elements tomeasure a component and detect a stain because the effect that a stainhas on the wavelength of light used is of importance in measuring acomponent.

In the above embodiments, the specimen includes blood. However, thespecimen is not limited to blood, but may be a body fluid such as urine,lymph fluid, cerebrospinal fluid, saliva, or the like, or a dilutesolution thereof, or a concentrated solution thereof.

The component to be measured (given component) is not limited to glucose(blood glucose level), but may be cholesterol, uric acid, creatinine,lactic acid, hemoglobin (occult blood), various alcohols, varioussugars, various protein, various vitamins, and various inorganic ionssuch as sodium.

In the above embodiments, an amount of a given component is measured.According to the present invention, however, a property of a givencomponent may be measured, or both an amount and a property of a givencomponent may be measured.

In the above embodiments, an O-ring (a sealing member made of anelastomeric material) is used as a representative sealing member.However, the sealing member may be made of any of various sealingmaterials (e.g., an adhesive) such as resin materials.

The component measuring devices according to the above embodiments areused in combination with a mounted tip having a test strip. Thecomponent measuring device according to the present embodiment mayemploy a tip in the form of a stick, a sheet, or any of other structures(forms).

INDUSTRIAL APPLICABILITY

According to the present invention, since dust, the specimen, or thelike is prevented from entering into the passage in the photometric unit(into the photometric unit), an amount of a blood component in questioncan be measured with high measurement accuracy. Even if dust, thespecimen, or the like is applied to the end of the photometric unit orthe like, it can easily and reliably be removed.

According to the present invention, furthermore, a stain on thelight-transmissive member can be detected with high accuracy. Since anamount of a blood component in question is prevented from being measuredwhile the light-transmissive member is being stained, the measurementaccuracy is increased. Since the component measuring device has thelight-transmissive member, dust, the specimen, or the like is reliablyprevented from entering into the passage in the photometric unit (intothe photometric unit), so that an amount of a blood component inquestion can be measured with high measurement accuracy.

Therefore, the present invention has industrial applicability.

1. A component measuring device for measuring at least one of a quantityor a property of a given component in a specimen by colorimetricallymeasuring a test member, comprising: a tip mount for removably mountinga tip having the test member; a photometric unit having a light-emittingelement for applying light to said test member of said tip formeasurement, a light-detecting element for detecting light reflected bysaid test member, and a holder in which is accommodated saidlight-emitting element and said light-detecting element; alight-shielding test tip for being removably mounted on said tip mount,wherein said holder has a passage for passing said light and saidreflected light therethrough, and a light-transmissive member isdisposed in a portion of said holder which is adapted to face said testmember; and stain detecting means for detecting a stain on saidlight-transmissive member based on an amount of light detected by saidlight-detecting element when light is emitted from said light-emittingelement while said test tip is mounted on said tip mount, wherein saidstain detecting means is arranged to determine that there is a stain onsaid light-transmissive member if an amount of light detected by saidlight-detecting element is greater than a threshold.
 2. The componentmeasuring device according to claim 1, wherein said test tip has alid-like member for covering a distal end of said tip mount.
 3. Thecomponent measuring device according to claim 2, wherein at least saidlid-like member of said test tip is black or dark in color.
 4. Thecomponent measuring device according to claim 2, wherein the distancefrom the distal end of said tip mount to an inner wall of said lid-likemember at a distal end thereof is 10 mm or greater while said test tipis mounted on said tip mount.
 5. A component measuring device formeasuring at least one of a quantity or a property of a given componentin a specimen by calorimetrically measuring a test member, comprising: aphotometric unit having a light-emitting element for applying light tosaid test member for measurement, and a light-detecting element fordetecting light reflected from said test member, wherein saidphotometric unit has a passage for passing said light and said reflectedlight therethrough, and a light-transmissive member is disposed in aportion of said photometric unit which is adapted to face said testmember; and stain detecting means for detecting a stain on saidlight-transmissive member based on an amount of light detected by saidlight-detecting element when light is emitted from said light-emittingelement, wherein said stain detecting means is arranged to determinethat there is a stain on said light-transmissive member if the amount oflight detected by said light-detecting element is greater than athreshold.
 6. The component measuring device according to claim 1,wherein a stain on said light-transmissive member is detected while saidtip is not mounted on said tip mount.
 7. The component measuring deviceaccording to claim 1, wherein a stain on said light-transmissive memberis detected when a power supply of the component measuring device isturned on.
 8. The component measuring device according to claim 1,having a stain detecting mode for detecting a stain on saidlight-transmissive member.
 9. The component measuring device accordingto claim 1, further comprising storage means for storing results fromthe stain detecting means, wherein a stain on said light-transmissivemember is detected after measurement, and a detected result is stored insaid storage means.
 10. The component measuring device according toclaim 9, wherein when a stain on said light-transmissive member is notdetected, information stored in said storage means is used.
 11. Thecomponent measuring device according to claim 9, wherein when thecomponent measuring device is powered on with said tip mounted on saidtip mount, a stain on said light-transmissive member is not detected andinformation stored in said storage means is used.
 12. The componentmeasuring device according to claim 1, further comprising indicatingmeans for indicating a detected result produced in detecting a stain onsaid light-transmissive member.
 13. The component measuring deviceaccording to claim 1, wherein said light-transmissive member closes saidpassage with a sealing member interposed therebetween.
 14. The componentmeasuring device according to claim 5, wherein a stain on saidlight-transmissive member is detected while said tip is not mounted onsaid tip mount.
 15. The component measuring device according to claim 5,wherein a stain on said light-transmissive member is detected when apower supply of the component measuring device is turned on.
 16. Thecomponent measuring device according to claim 5, having a staindetecting mode for detecting a stain on said light-transmissive member.17. The component measuring device according to claim 5, furthercomprising storage means for storing results from the stain detectingmeans, wherein a stain on said light-transmissive member is detectedafter measurement, and a detected result is stored in said storagemeans.
 18. The component measuring device according to claim 5, furthercomprising indicating means for indicating a detected result produced indetecting a stain on said light-transmissive member.
 19. The componentmeasuring device according to claim 5, wherein said light-transmissivemember closes said passage with a sealing member interposedtherebetween.